A nanoimprint method is available as a microprocessing method needed for the production of a semiconductor integrated circuit or the like. The nanoimprint method is a method including curing a curable composition applied to a substrate with light, heat, or the like under a state in which a mold having formed thereon a fine irregular pattern is pressed against the curable composition; and transferring the irregularities of the mold onto the curable composition on the substrate to produce a cured film. The employment of the method enables the production of a cured film having a pattern shape imitating the irregular shape of the mold.
In recent years, vigorous researches have been conducted on a curable composition to be used in the nanoimprint method. Japanese Patent Application Laid-Open No. 2006-528088 (PTL 1) discloses a method of producing a cured film, including applying a curable composition containing a surfactant as an internal addition type release agent onto a substrate so that the surfactant may be unevenly distributed at a high concentration toward the upper layer of the curable composition at the stage of the application onto the substrate.
However, conventional methods including PTL 1 have involved the following problem. Although the releasability of a cured film is excellent, the filling speed of a curable composition required when a mold is pressed against the curable composition to fill the curable composition into its fine irregular pattern is slow.